xsk: add new netlink attribute dedicated for ZC max frags

Introduce new netlink attribute NETDEV_A_DEV_XDP_ZC_MAX_SEGS that will
carry maximum fragments that underlying ZC driver is able to handle on
TX side. It is going to be included in netlink response only when driver
supports ZC. Any value higher than 1 implies multi-buffer ZC support on
underlying device.

Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Link: https://lore.kernel.org/r/20230719132421.584801-11-maciej.fijalkowski@intel.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This commit is contained in:
Maciej Fijalkowski
2023-07-19 15:24:07 +02:00
committed by Andrii Nakryiko
parent 4cd8e50d37
commit 8ae70bcbdf
3 changed files with 8 additions and 1 deletions

View File

@@ -41,6 +41,7 @@ enum {
NETDEV_A_DEV_IFINDEX = 1,
NETDEV_A_DEV_PAD,
NETDEV_A_DEV_XDP_FEATURES,
NETDEV_A_DEV_XDP_ZC_MAX_SEGS,
__NETDEV_A_DEV_MAX,
NETDEV_A_DEV_MAX = (__NETDEV_A_DEV_MAX - 1)

View File

@@ -1105,9 +1105,10 @@ struct bpf_xdp_query_opts {
__u32 skb_prog_id; /* output */
__u8 attach_mode; /* output */
__u64 feature_flags; /* output */
__u32 xdp_zc_max_segs; /* output */
size_t :0;
};
#define bpf_xdp_query_opts__last_field feature_flags
#define bpf_xdp_query_opts__last_field xdp_zc_max_segs
LIBBPF_API int bpf_xdp_attach(int ifindex, int prog_fd, __u32 flags,
const struct bpf_xdp_attach_opts *opts);

View File

@@ -45,6 +45,7 @@ struct xdp_id_md {
struct xdp_features_md {
int ifindex;
__u32 xdp_zc_max_segs;
__u64 flags;
};
@@ -421,6 +422,9 @@ static int parse_xdp_features(struct nlmsghdr *nh, libbpf_dump_nlmsg_t fn,
return NL_CONT;
md->flags = libbpf_nla_getattr_u64(tb[NETDEV_A_DEV_XDP_FEATURES]);
if (tb[NETDEV_A_DEV_XDP_ZC_MAX_SEGS])
md->xdp_zc_max_segs =
libbpf_nla_getattr_u32(tb[NETDEV_A_DEV_XDP_ZC_MAX_SEGS]);
return NL_DONE;
}
@@ -493,6 +497,7 @@ int bpf_xdp_query(int ifindex, int xdp_flags, struct bpf_xdp_query_opts *opts)
return libbpf_err(err);
opts->feature_flags = md.flags;
opts->xdp_zc_max_segs = md.xdp_zc_max_segs;
skip_feature_flags:
return 0;